Security is a major concern in our day to day life, and digital locks have become an important part of these security systems. There are many types of security systems available to secure our place. Some examples are PIR based Security System, RFID based Security System, Digital Lock System, bio-matrix systems, Electronics Code lock. In this post, we will Interface a Fingerprint Sensor Module with Arduino and will build a Fingerprint based Biometric Security System with door locking. Finger Print is considered one of the safest key to lock or unlock any system as it can recognize any person uniquely and can’t be copied easily.

Components Required:

Arduino Uno

Finger Print Module

Push Button -4

LEDs -2

1K Resistor -3

2.2K resistor -1`

Power Supply

Connecting wires

Cardboard Box

Servo Motor -1

16x2 LCD -1

Bread Board -1

Finger Print Sensor Module with Arduino:

Finger Print Sensor Module or Finger Print Scanner is a module which captures finger’s print image and then converts it into the equivalent template and saves them into its memory on selected ID (location) by Arduino. Here all the process is commanded by Arduino like taking an image of finger print, convert it into templates and storing location etc.

In this Arduino Fingerprint Sensor Project, we have used Fingerprint Sensor Module to take finger or thumb impression as input in the system. Here we are using 4 push buttons to Enroll/back, Delete/OK, UP and Down. Every key has double features. Enroll key is used for enrolling new finger impression into the system and back function as well. Means when the user wants to enroll new finger then he/she needs to press enroll key then LCD asks for the ID or Location where user wants to store the finger print output. Now if at this time user do not want to proceed further then he/she can press enroll key again to go back (this time enroll key behave as Back key). Means enroll key has both enrollment and back function. DEL/OK key also has same double function like when user enrolls new finger then he/she need to select finger ID or Location by using another two key namely UP/MATCH AND DOWN/MATCH (which also has double function) now user needs to press DEL/OK key (this time this key behaves like OK) to proceed with selected ID or Location. UP/DOWN keys also support Finger print match function. Check the Video at the end for full demonstration.

Here we have also attached a cardboard box with a Servo Motor to act as a security gate, which will only open when the system will read correct Finger Print. Yellow LED indicates gate is closed and Green LED indicates gate is opened.

Working Explanation:

Working of this Fingerprint Sensor Door Lock is easy. In this project, we have used a gate that will be open when we place stored finger at the finger print module. First of all, the user needs to enroll finger with the help of push button/keys. To do this user need to press ENROLL key and then LCD asks for entering location/ID where finger will be a store. So now user needs to enter ID (Location) by using UP/DOWN keys. After selecting Location/ID user needs to press an OK key (DEL key). Now LCD will ask for placing finger over the finger print module. Now user needs to put his finger over finger print module. Then LCD will ask to remove the finger from finger print module and again ask for placing the finger. Now user needs to put his finger again over finger print module. Now finger print module takes an image and converts it into templates and stores it by selected ID in to the finger print module’s memory. Now user can open the gate by placing the same finger that he/she have added or enrolled into the system and then press MATCH key (UP/Down key). By the same method, the user can add more fingers. Check the Video below for full demonstration.

Now if the user wants to remove or delete any of stored ID then he/she need to press DEL key, after pressing DEL key, LCD will ask for select location means select ID that to be deleted. Now user needs to select ID and press OK key (same DEL key). Now LCD will let you know that finger has been deleted successfully. Now the user may check it was deleted or not by placing the same finger over the finger print module and pressing MATCH key (UP/Down key).

When placed finger will be valid Green LED will glow for five second and gate also opens at the same time. After 5-seconds gate will be closed automatically. The user may customize gate/door opening and closing according to their requirement. Servo motor is responsible for open and closing of the gate.

Circuit Explanation:

The circuit of this Arduino Fingerprint Security System is very simple which contains Arduino which controls whole the process of the project, push button, buzzer, and LCD. Arduino controls the complete processes.

The push button is directly connected to pin D14(ENROL),D15(DEL), D16(UP) and D17(DOWN) of Arduino with respect to ground And Yellow LED is connected at Digital pin D7 of Arduino with respect to ground through a 1k resistor and Green LED is connected to D6 of Arduino with the same method. Finger Print Module’s Rx and Tx directly connected at Software Serial or Digital pin D2 and D3 of Arduino. 5v supply is used for powering finger print module taken from Arduino board and Servo motor is also connected to PWM pin D5 of Arduino. A 16x2 LCD is configured in 4-bit mode and its RS, EN, D4, D5, D6, and D7 are directly connected at Digital pin D13, D12, D11, D10, D9, and D8 of Arduino.

Note: here D14, D15, D16, D17 are A0, A1, A2, A3 respectively.

Program Explanation:

In a program, we have used Adafruit Fingerprint Sensor Library for interfacing fingerprint module with Arduino board. You can check the complete Code below, it can be easily understood. Here we are explaining main functions of the Arduino Program.

Below piece of code is used to take Finger Print as input and take action according to validation of finger. If finger will be validated gate will be open otherwise remain closed.

Given void checkKeys() function is used for checking Enroll or DEL key is pressed or not and what to do if pressed. If the ENROL key pressed the Enroll() function is called and DEL key press then delete() function is called.

good day sir, please sir, i am currently working on this project as my final year project, i have purchased everything and just when i tried to compile the code in my ide, i got this error message "'class Adafruit_Fingerprint' has no member named 'deleteMode " and then i removed that very line of code and re compiled it but i got another error message "collect2.exe: error: ld returned 1 exit status" i am very confused right now, i need your help. i have less than a month to submit this project to my department...than you

This project is very helpful for my final year project. Sir I need to save the finger print access whenever user access the fingerprint. i want save the access log report with time. Please give code for eeprom and rtc with this program. Thank you

hello my friend how are , i have this project for the final project i want to operate the circuit but i dont know because there's problem but i don't know how to solved it , if have any ideas please reply me .
thanks ✋

Hlo sir, I really like this project and I'm choosing it for my final year project. Please I would like to know if there is any improvement that can be add on on this project. I would really appreciate it if there is.

hiii sir,
the problem i'am facing here in the display of lcd , it displays the boxes initially as shown in your video but after that nothing displays but if it is incorporated with another arduino then it displays.....what may be the problem....mine arduino board is in operational mode no problem with arduino kit....

I am using fingerprint module r307 and LCD together. In that, I am using 2,3 digital pins of arduino for data transfer to the fingerprint.(I tried other pin configurations for this but it didn't work) But as I am connecting LCD, it also requires same 2,3 digital pins of arduino and it is not possible for me to use 2 and 3 pins of Arduino for both lcd and fingerprint sensor for data transfer. Can you please suggest an alternative to this. Can we use analog pins of arduino as digital ones and if so the how?? PLEASE HELP... Thank you!!